Which ef the tollowing it the general selusian of 4y′′ i y=0 ? v(t)=ϵ1​et+c2​ettv(t)=c1​ct/+ϵj​et/2w(t)=c1​cos(t/2)+c2​sin(t/2)​ v(t)=c1​et+c2​e−1